Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c8110903b1208b3…

MALICIOUS

PDF

75.0 KB Created: 2021-03-15 00:02:50 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 8fe4d4eb917d0957047bcb9c2a66e067 SHA-1: 242b9d389e29a54925a6ed8c7d79e4e42e39fe20 SHA-256: 4c8110903b1208b37cb290098aa37ff496e6a064532d15a86c827b2958c0d01d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external links, a technique often used for SEO spam or to redirect users to malicious sites. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically identified as a phishing trojan. While no scripts were directly extracted, the PDF structure and embedded URLs suggest an attempt to drive traffic to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://resalured.ru/wix?keyword=biology+dna+replication+worksheet
    • https://cdn.sqhk.co/dinigivo/aaJYqge/luribelabopixetej.pdf
    • https://cdn.sqhk.co/fofodafexadu/irCjeWH/teddy_bridgewater_vikings.pdf
    • https://cdn.sqhk.co/rifarako/jftojfk/pumilutovikiguf.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://piterar.epizy.com/bujemupivozof.pdf
    • https://uploads.strikinglycdn.com/files/9c47079e-4f9a-41f3-8514-4c3623df4130/continuidad_de_los_parques_analisis_titulo.pdf
    • https://a72a44ae-2aae-4d6a-a6c4-235301d0a62e.filesusr.com/ugd/57436b_c164299c46a4473888edff94d2330c26.pdf?index=true
    • https://uploads.strikinglycdn.com/files/e1b2751c-3d00-46ad-9e75-7b600a2cb184/pufexesovip.pdf
    • https://cc968bdf-8a18-4a65-a72d-893c706ef441.filesusr.com/ugd/bae363_06609d96f9d04046b5c40267c0c41879.pdf?index=true
    • https://s3.amazonaws.com/xuzed/toxokejipebilajex.pdf
    • https://1e438cd7-6f3b-42ac-a97b-d13a75fa135b.filesusr.com/ugd/0c268c_22d015ebfa274cfc8d69818f6d3b3857.pdf?index=true
    • http://tasopawak.rf.gd/autocad_lt_3d_printing.pdf
    • https://uploads.strikinglycdn.com/files/262e2ed6-a921-4681-9b7d-7bf78b5199aa/frick_natural_gas_screw_compressors.pdf
    • https://uploads.strikinglycdn.com/files/66718c6d-cff3-425b-a8c6-bb01b19632c2/37523650703.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e722.bin
1b19613ba06046a9e096df616078acac67d88a41e6a4c39bbef764d147171e3e
pdf-font-stream PDF embedded font (sfnt) at offset 0xE722 5644 bytes
font_01_sfnt_off0000fa71.bin
808c80dec3a0330938b954a5e6a8f1fce72995603cbf58e7bb62583c86768867
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA71 10804 bytes